CUSTOMER_CODE
SMUDE
DIVISION_CODE
SMUDE
EVENT_CODE
SMUAPR15
ASSESSMENT_CODE BT0075_SMUAPR15
QUESTION_TYPE DESCRIPTIVE_QUESTION
QUESTION_ID
6393
QUESTION_TEXT Describe Log File Maintenance .
SCHEME OF
EVALUATION
MySQL Server can create a number of different log files that make it
easy to see what is going on. However, you must clean up these files
regularly to ensure that the logs do not take up too much disk space.
When using MySQL with logging enabled, you may want to backup
and remove old log files from time to time and tell MySQL to start
logging new files.
On a Linux (Red Hat) installation, you can see the mysql-log-rotate
script for this. If you installed MySQL from an RPM distribution, this
script should have been installed automatically. You should be careful
with this script if you are using a binary log or replication.
You should not remove binary logs until you are certain that their
contents have been processed by all slaves.
On other systems, you must install a short script yourself that you start
from cron (or its equivalent) for handling log files.
For the binary log you can set the expire_logs_days system variable to
expire binary log files automatically after a given number of days. If
you are using replication, you should set the variable no lower than
the maximum number of days your slaves might tag behind the
master.
You can force MySQL to start using new log files by issuing a
FLUSH LOGS statement or executing mysqladmin flush-logs or
mysqladmin refresh.
(3 Marks)
A log flushing operation does the following:
1.If general query logging or slow query logging to a log file is
enabled, the server closes and reopens the general query log file or
slow query log file.
2.If binary logging is enabled, the server closes the current binary log
file and opens a new log file with the next sequence number.
3.If the server was given an error log filename with the –log-error
option, it renames the error log with the suffix –odd and creates a new
empty error log file.
(3 Marks)
The server creates a new binary log file when you flush the logs.
However, it just closes and reopens the general and slow query log
files. To cause new files to be created on Unix, rename the current
logs before flushing them. At flush time, the server will open new logs
with the original names. For example, if the general and slow query
logs are named mysql.log and mysql-slow.log you can use a series of
commands like this:
shell> cd mysql-data-directory
shell> mv mysql.log mysql.old
shell> mv mysql-slow.log mysql-slow.old
shell>mysqladmin flush-logs
At this point, you can make a back of mysql.old and mysql-slow.log
and then remove from the disk.
(2 Marks)
Before 5.1.3 you cannot remove a log file on Windows while a server
has it open. You must stop the server and rename the file and then
restart the server to create a new log file. As of 5.1.3, this applies only
to the error log. However, a stop and restart can be avoided by using
FLUSH LOGS, which causes the server to rename the error log with
an –old suffix and open a new error log.
As of MySQL 5.1.2, you can disable the general query log or slow
query log at runtime.
SET GLOBAL general_log = ‘OFF’;
SET GLOBAL slow_query_log = ‘OFF’;
With logs disabled, rename the log files externally, for example, from
the command line. Then enable the logs again:
SET GLOBAL general_log = ‘ON’;
SET GLOBAL slow_query_log = ‘ON’;
This method works on any platform and does not require a server
restart. (2 Marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
73282
QUESTION_TEXT
Describe various logical operators in MySQL.
The NOT operator
The OR operator
SCHEME OF EVALUATION The XOR operator
Bit operator
Explanation(2.5 each)
QUESTION_T
DESCRIPTIVE_QUESTION
YPE
QUESTION_I
D
115895
Write and explain the syntax of
QUESTION_T
a.
EXT
DROP TABLE
b.
DROP INDEX
c.
a)
DROP DATABASE
DROP TABLE: (04 marks)
DROP [TEMPORARY] TABLE [IF EXISTS]
tbl_name [, tbl_name] ...
[RESTRICT | CASCADE]
*
DROP TABLE removes one or more tables.
*
You must have the DROP privilege for each table.
*
All table data and the table definition are removed.
*
If any of the tables named in the argument list do not exist, MySQL
returns an error indicating by name which non existing tables it was unable
to drop, but it also drops all of the tables in the list that do exist.
SCHEME OF
EVALUATIO
N
*
DROP TABLEautomatically commits the current active transaction,
unless you use theTEMPORARY keyword.
The TEMPORARY keyword has the following effects:
*
The statement drops only TEMPORARY tables.
*
The statement does not end an ongoing transaction.
*
No access rights are checked
b)DROP INDEX: (02 marks)
DROP INDEX index_name ON tbl_name
DROP INDEX drops the index named index_name from the
table tbl_name.
This statement is mapped to an ALTER TABLE statement to drop the
index.
Example:
Mysql>DROP INDEX usrname on sysusers;
c) DROP DATABASE:
(04 marks)
DROP {DATABASE | SCHEMA} [IF EXISTS] db_name
*
DROP DATABASE drops all tables in the database and deletes the
database.
*
To use DROP DATABASE, you need the DROP privilege on the
database.
*
DROP SCHEMA is a synonym for DROP DATABASE.
When a database is dropped, user privileges on the database are
not automatically dropped.
*
IF EXISTS is used to prevent an error from occurring if the database
does not exist.
*
If you use DROP DATABASE on a symbolically linked database,
both the link and the original database are deleted.
*
DROP DATABASE returns the number of tables that were removed.
This corresponds to the number of .frm files removed.
*
The DROP DATABASE statement removes from the given database
directory those files and directories that MySQL itself may create during
normal operation:
All files with the following extensions.
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
115897
Explain the following in detail
a.
Error Log
b.
General Query Log
c.
Binary Log
d.
Slow Query Log
a)
Error Log:
QUESTION_TEXT
( 2.5 MARKS)
*
The error log contains information indicating when mysqld
was started and stopped and also any critical errors that occurs
while the server is running.
*
If mysqld notices a table that needs to be automatically
checked or repaired,it writes a message to error log.
SCHEME OF
EVALUATION
b)
The General Query Log:
( 2.5 MARKS)
*
It is a general record of what mysqld is doing.
*
The server writes information to this log when client connect
or disconnect, and it logs each SQL statement received from clients.
*
It is useful when you suspect an error in a client and want to
know exactly what the clients sent to mysqld.
c)
The Binary Log:
( 2.5 MARKS)
*
All the information that update data.
*
It also contains statements that potentially could have updated
it, unless row-based logging is used.
*
Statements are stored in the form of “events” that describe
the modifications.
*
It also contains information about how long each statement
took that updated data.
d)
The Slow Query log:
( 2.5 MARKS)
*
It consists of all statements that took more than long-querytime seconds to execute and required at least
min_examined_row_limit rows to be examined.
*
The time to acquire the initial table locks is not counted as
execution time.
QUESTION_TYPE DESCRIPTIVE_QUESTION
QUESTION_ID
115898
What are the reasons to use MySQL? What is new in MySQL 5.1?
QUESTION_TEXT
The reasons to use MySQL:
[Any 5. 1 Mark Each. 5 x 1 Mark = 5 Marks]
SCHEME OF
EVALUATION
1.
Scalability and Flexibility:The MySQL database server provides
the ultimate in scalability, sporting the capacity to handle deeply
embedded applications with a footprint of only 1MB to run massive
data warehouses holding terabytes of information. Platform flexibility
is a stalwart feature of MySQL with all flavors of Linux, UNIX, and
Windows being supported.
2.
High Performance: A unique storage-engine architecture allows
database professionals to configure the MySQL to database server
specifically for particular applications, with the end result being
amazing performance results.
3.
High Availability: MySQL offers a variety of high-availability
options from high-speed master/slave replication configurations, to
specialized Cluster servers offering instant failover, to third party
vendors offering unique high-availability solutions for the MySQL
database server.
4.
Robust Transactional Support:MySQL offers one of the most
powerful transactional database engines on the market. Full data
integrity is also assured through server-enforced referential integrity,
specialized transaction isolation levels, and instant deadlock
detection.
5.
Web and Data Warehouse Strengths:MSQL is the de-facto
standard for high-traffic web sites because of its high-performance
query engine, tremendously fast data inserts capability, and strong
support for specialized web functions like fast full text searches.
6.
Strong Data Protection:Because guarding the data assets of
corporations is the number one job of database professionals, MySQL
offers exceptional security features that ensure absolute data
protection.
7.
Comprehensive Application Development:MySQL also
provides connectors and drivers (ODBC, JDBC, etc.) that allow all
forms of applications to make use of MYSQL as a preferred data
management server.
8.
Management Ease:MySQL provides a complete suite of
graphical management and migration tools that allow a DBA to
manage, troubleshoot, and control the operation of many SQL servers
from a single workstation.
9.
Open Source Freedom and 24x7 Support:MySQL is not a
typical open source project as all the software is owned and supported
by MySQL AB, and because of this, a unique cost and support model
are available that provides a unique combination of open source
freedom and trusted software with support.
10. Lowest Total Cost of Ownership:By migrating current databasedrive applications to MySQL, or using MySQL for new development
projects, corporations are realizing cost savings that many times
stretch into seven figures.
(5 Marks)
New in MySQL 5.1: The following features have been added to
MySQL 5.1
[Any 5. 1 Mark Each. 5 x 1 Mark = 5 Marks]
1.
Partitioning:This capability enables distributing portions of
individual labels across a file system, according to rules which can be
set when the table is created. In effect, different portions of a table are
stored as separate tables in different locations, but from the user point
of view, the partitioned table is still a single table.
2.
Row-Based Replication: Replication capabilities in MySQL
originally were based on propagation of SQL statements from master
to slave. This is called statement-based replication. As of MySQL
5.1.5 another basis for replication is available. This is called rowbased replication, instead of sending SQL statements to the slave, the
master writes events to its binary log that indicate how individual
table rows are affected. As of MySQL 5.1.8 a third options is
available; mixed. This will use statement-based replication by default,
and only switch to row-based replication in particular cases.
3.
Plugin API: MySQL adds support for a very flexible plugin API
that enables loading and unloading of various components at runtime,
without restarting the server. This allows users to implement their
own input filter on the indexed text, enabling full-text search
capability on arbitrary data such as PDF files or other document
formats.
4.
Event Scheduler: MySQL events are tasks that run according to
a schedule. When you create an event, you are creating a named
database object containing one or more SQL statements to be
executed at one or more regular intervals, beginning and ending at a
specific date and time.
5.
Server Log Tables: As of MySQL 5.1, the server’s logging
capabilities are more flexible. Log entries can be written to log files
or to the general_logand slow_log tables in the MySQL databases. If
logging is enabled, either or both destinations can be selected. The –
log-output option controls the destination or destinations of log
output.
6.
Upgrade Program: The MySQL_upgrade program checks all
existing tables for incompatibilities with the current version of
MySQL Server and repairs them if necessary. This program should be
run for each MySQL upgrade.
7.
MySQL Cluster: Clustering support is longer available in
mainline MySQL 5.1 releases. MySQL cluster releases are identified
by a 3-part NDT version number; currently, the MySQL Cluster NDB
6.2 and MySQL. Cluster NDB 6.3 release series are available for
production use.
(5 Marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
115902
QUESTION_TEXT
Describe different storage engines.
i.
Archive
ii.
CSV
SCHEME OF EVALUATION iii.
Example
iv.
Federated
v.
Heap